1. Technical Field
Exemplary embodiments of the present invention relate to a touch screen substrate and a method of manufacturing the touch screen substrate. More particularly, exemplary embodiments of the present invention relate to a touch screen substrate that improves the reliability of a manufacturing process and a method of manufacturing the touch screen substrate.
2. Discussion of the Related Art
Generally, a liquid crystal display (LCD) panel includes a first substrate having switching elements for driving pixels, a second substrate facing the array substrate, and a liquid crystal layer interposed between the first and second substrates. Liquid crystal molecules in the liquid crystal layer control light transmittance according to an electric field applied to the liquid crystal layer so that the LCD panel displays an image.
The LCD panel functions as a touch panel operating in response to an external pressure. The second substrate of the touch panel includes a photo sensor and a switching element controlling the photo sensor. When the external pressure is exerted upon the LCD panel, light generated from a backlight disposed under the LCD panel is reflected by a foreign object touching the panel and then is provided to the photo sensor, and thus the photo sensor absorbs the reflected light to generate a photo current. A central processing unit connected to the LCD panel calculates a touch position based on a difference between the photo current and a dark current generated by the photo sensor before the light is incident to the photo sensor.
When the external pressure is exerted upon the LCD panel, the reflected light and external light different from the reflected light may be together provided to the photo sensor. The photo sensor senses the external light as well as the reflected light so that the central processing unit does not exactly calculate the touch position. In order to address this issue, a light blocking pattern is formed under the photo sensor, and the light blocking pattern transmits necessary light having a specific wavelength and prevents the external light from being provided to the photo sensor.
However, when the light blocking pattern is not uniformly formed on the second substrate, a plurality of upper patterns formed on the light blocking pattern may not be uniformly formed on the second substrate because the light blocking pattern is a pattern firstly formed on the second substrate. Thus, the reliability of a manufacturing process of the upper patterns may be reduced.